Aerosol-generating devices

ABSTRACT

An aerosol generating device comprises two reservoirs, each arranged to contain a separate aerosol producing composition; means for drawing the compositions from the reservoirs to generate an aerosol for inhalation for a user, and means for mixing the compositions after they have been drawn from the reservoirs, the mixing means being arranged to allow a user to select the relative proportions of the two compounds in the aerosol.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/390,150, filed on Oct. 2, 2014, now U.S. Pat. No. 9,936,731,which is a national stage application under 35 U.S.C. § 371 ofInternational Application No. PCT/EP2013/051011, filed Jan. 21, 2013,published in English, which claims priority from European PatentApplication No. 12163871.2, filed 1-0 Apr. 12, 2012, all of which areincorporated by reference herein in their entireties.

FIELD OF THE INVENTION

The present invention relates to aerosol-generating devices, inparticular electronic cigarettes.

BACKGROUND OF THE INVENTION

Traditional approaches to generating aerosol often do not use heatenergy, and include pressurised containers with valves, dry powderformulations or nebulisers.

Electronic cigarettes are relatively well known in the art and arebecoming popular as a substitute for a regular cigarette. The mostcommon operating principle for such electronic cigarettes is to providea flavoured aerosol to a user without burning material. Such an aerosolcan comprise inhalable mixtures of gases, liquid aerosols (liquidparticles suspended in air) and/or solid aerosols (solid particlessuspended in air). One of the most common approaches to providing theflavoured aerosol is to have a reservoir of aerosol-generating liquidwhich is vaporised by provision of an electrically powered heat sourceto which the liquid is provided.

Aerosol-generating liquids typically contain, in varying proportions, atleast one aerosol producer (often propylene glycol and/or glycerol),diluents (water and/or ethanol), flavours and/or tobacco extracts, andaroma compounds.

Some prior art electronic cigarettes operate through a user depressing aswitch which activates the heating process after which they can inhalefrom the electronic cigarette. Others have an activation switch for theheater which is operated when a user inhales and draws air through theelectronic cigarette.

Whilst such electronic cigarettes are becoming popular, consumers seemto experience some problems with them. For example, it can be difficultfor the user to control the level of intensity or strength of flavourthat is delivered to them. Attempts have been made to overcome this byhaving a control over the element that creates the aerosol, but suchdevices often provide such low level of aerosol at some settings thatconsumers dislike them.

Furthermore, some compounds in the aerosol-generating liquid that areused to provide flavour to the aerosol can lose aroma character overtime. As an example, vanillin, a vanilla flavour component, reacts withpropylene glycol when mixed, reducing the flavour generated by thevanillin and also producing a deep red discolouration in theaerosol-generating liquid.

The present invention seeks to provide an aerosol generating devicewhich overcomes at least some of the above problems.

According to the present invention there is provided an aerosolgenerating device comprising:

-   -   at least two reservoirs, each arranged to contain a separate        aerosol producing composition;    -   means for drawing the compositions from the reservoirs to        generate an aerosol for inhalation for a user, and    -   means for mixing the compositions after they have been drawn        from the reservoirs, the mixing means being arranged to allow a        user to select the relative proportions of the two compounds in        the aerosol.

In a preferred embodiment of the invention the aerosol generating deviceis an electronic cigarette and comprises:

-   -   a power source;    -   at least one heater assembly;    -   a means for selectively applying power from the power source to        the heater assembly;    -   at least two liquid-containing reservoirs, each arranged to        contain a separate aerosol producing composition; and    -   control means for selectively controlling the heating of liquid        from one or more of the reservoirs by the heater assembly, such        that, when power is supplied to the heater assembly together        with the selected liquid, an aerosol is generated for inhalation        by a user.

With the present invention, it is possible for a user to control thecontent of the aerosol that they receive by controlling the source ofthe liquid.

This control may also allow the mixing of components during aerosolgeneration such that they are not mixed in advance and therefore notsubject to adverse aging effects.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the present invention will now be described with referenceto the accompanying drawings, in which:

FIG. 1 is a schematic diagram showing a conventional electroniccigarette;

FIG. 2 is a schematic diagram showing the operation of a conventionalelectronic cigarette;

FIGS. 3A to 3C are schematic diagrams of example reservoir componentsfor electronic cigarettes according to the present invention;

FIG. 4 shows example approaches for activating a heater assembly in theexamples of FIGS. 3A to 3C;

FIG. 5 is a schematic diagram showing a further example of the presentinvention and its operation;

FIG. 6 is a schematic diagram showing a further example of the presentinvention and its operation;

FIG. 7 is a schematic diagram showing a further example of the presentinvention;

DETAILED DESCRIPTION

Referring to FIG. 1 an example prior art electronic cigarette 1 has aliquid reservoir 2 containing an aerosol-generating liquid. The liquidreservoir 2 is fluidly connected to a heater assembly 3, the fluidconnection in this example being provided by a porous metal bridge 4(for example, foamed nickel) and a transfer element 5. The transferelement 5 typically operates by capillary action, and can take variousphysical forms, such as heat-resistant fibres of glass or ceramic,narrow-diameter capillary tubes or various other porous materials. Theheater assembly 3 comprises a heating filament connected to a battery 6via a switch 7 to heat the transfer element 5 such that a liquidtransferred by capillary action in the transfer element 5 is vaporisedat its surface under heat conduction from the heater assembly 3 to thetransfer element 5. In operation the switch 7 is activated either bydepression by a user or by detection of air being drawn through theelectronic cigarette 1 by a user. This enables the supply of currentfrom the battery 6 to the heater assembly 3 which heats and vaporisesliquid in the transfer element 5 which then passes into the air stream 8within the electronic cigarette 1 and out through to a user forinhalation.

FIG. 2 shows some of the key components of FIG. 1 to explain in moredetail operation of an electronic cigarette. Here the liquid reservoir 2supplies liquid via a capillary action to the transfer element 5, thetransfer element 5 being selectively heated by the heater assembly 3.Air flow over the transfer element 5 is indicated by the arrows whichshow how air is drawn over the transfer element 5, the heater assembly 3then heating a very small (but constant) quantity of the liquid andboiling it into gas to generate an aerosol which is delivered to a user.With appropriate control of the air flow the gases cool quickly to allowa carrier in the liquid (usually propylene glycol or glycerol), tocondense into microscopic droplets which are visible as a densesmoke-like aerosol which is provided to a user.

As mentioned above, such electronic cigarettes have significant benefitsin view of their non-combustible generation of an aerosol, allowingusers to use them in areas where regular cigarette use would berestricted. However, variance in the air flow or ageing of the liquidcan lead to problems in terms of delivering an appropriate quality ofaerosol to a user. It can also be difficult for the user to control thelevel of intensity or strength of flavour that is delivered to them.

The present invention proposes, as will now be described with referenceto FIG. 3a to FIG. 3c , a new kind of aerosol generating device such asan electronic cigarette 10 in a first preferred embodiment, whichovercomes some of these problems. In these figures components whichcorrespond to those in the earlier figures are numbered identically. Forsimplicity of illustration, certain components have been removed fromillustration, such as the porous metal bridge 4 and transfer element 5,as well as switch 7, although these may well be present dependent uponparticular end consumer requirements, as will be appreciated by a personskilled in the art.

Referring to FIG. 3a , the electronic cigarette 10 of the inventioncomprises an elongated body 11, for instance cylindrical. At an end ofsaid elongated body 11 a mouthpiece 12 is provided for a user to placethe electronic cigarette 10 at his mouth to draw air into the electroniccigarette 10 through at least one air intake 13 to produce an aerosolthat can be then inhaled. The elongate body 11 of the electroniccigarette 10 accommodates a battery 6 to provide an electrical supply toa heater assembly 3.

Compared to the electronic cigarette 1 shown in FIGS. 1 and 2, theelectronic cigarette 10 of the present invention further comprises atleast two liquid reservoirs 20, 21 in working arrangement with theheater assembly 3. Each reservoir 20, 21 contains an aerosol producingcomposition, with at least one of said reservoirs 20, 21 preferablycontaining a flavorant. Moreover, in this embodiment the heater assembly3 comprises a first and a second heating elements 31, 32 for each of thetwo liquid reservoirs 20, 21. Both reservoirs 20, 21 are in the presentembodiment located in the mouthpiece 12 section of the body 11 of theelectronic cigarette 10 and preferably contain an aerosol producingcomposition to produce an aerosol when air is drawn from the mouthpiece12 of the elongate body 11 by a user.

In the embodiment of FIG. 3a , control means for supplying power fromthe battery 6 to the heater assembly 3 and actuation of the heatingelements 31, 32 is further provided. The control means at leastcomprises an electric switch 14 provided on the external surface of theelongate body 11 of the electronic cigarette 10. The control means canalso comprise indicators or any kind of power supply circuitry toindividually power the heating elements 31, 32. For instance, thecontrol means can be arranged to allow alternately pulsed power supplyto each of the heating elements 31, 32 of the heater assembly. Suchpulsed alternate power supply of the heating elements 31, 32 can allowthe user to selectively and successively produce aerosol from each ofthe two reservoirs 20, 21 and thereby adjust the flavour profile of theaerosol.

In operation, a user can operate the selector switch 14 to determinewhich of the heating elements 31, 32 is activated, and as such selectwhich liquid from which reservoir 20, 21 is heated to provide aerosol.By provision of two reservoirs 20, 21 it is therefore possible for auser to select and adjust the aerosol that is inhaled to vary theflavour or composition in accordance with their particular needs at anymoment or location.

FIG. 3b shows a second embodiment of the electronic cigarette 10 of theinvention, which again has two reservoirs 20, 21 located in themouthpiece section 12 of the elongated body 11 of the electroniccigarette 10. In this case, the heater assembly 3 also comprises twoheating elements 31, 32, one for each reservoir 20, 21, both beingsupplied by a battery 6. In that second embodiment, the control meanscomprises a switch which is actuated by twisting the mouthpiece section12 of the electronic cigarette 1 which contains the reservoirs 20, 21 ofthe elongate body 11. This selects which of the heating elements 31, 32is powered and the reservoir 20, 21 delivering liquid to produce anaerosol when an air flow passes through the electronic cigarette 1 whena user draws a puff from the mouthpiece section 12.

FIG. 3c shows a third embodiment of an electronic cigarette 10 accordingto the present invention. In that third embodiment the control means ofthe electronic cigarette comprises a selectable valve 15 positionedadjacent to two bridges 16 which connect to respective reservoirs 20,21. In this example the heater assembly 3 comprises a single heatingcoil 33 provided with a central transfer element 5. In operation in thiscase, a user can move the valve 15 to select one of the two reservoirs20, 21 delivering liquid that generates the aerosol or can select amixture of the two to alter the level of flavour or, indeed, activatethe mixing of two at the moment of inhalation to prevent negative agingeffects by the two liquids being mixed too soon before aerosolgeneration.

The electronic cigarette 10 of the invention as depicted in FIGS. 3a to3c can be a single use, disposable electronic cigarette or a multipleuse device. In the case of a multiple-use device, the reservoirs 20, 21can be made to be either disposable or refillable with an aerosolproducing composition of a user's choice. In that case, is it preferredthat the mouthpiece section 12 of the elongate body 11 of the electroniccigarette 10 is detachable from said body 11 so as to let a user accessthe reservoirs 20, 21 to either replace or refill it. The mouthpiece 12section itself can also be disposable for hygiene purposes. In addition,the reservoirs can eventually be positioned in the mouthpiece itself.

The battery 6 can also be a disposable battery or a rechargeablebattery, preferably of a lithium ion rechargeable type as alreadycommonly used in electronic cigarettes.

FIG. 4 shows a number of example approaches to controlling the heatingassembly of the present invention in the case of example of FIG. 3a . Itwill be appreciated that similar approaches could be taken when theother examples either through control of separate heating elementswithin the heater assembly or by control of the flow of liquid to asingle heater assembly. As shown in FIG. 4a in a first example the“average” voltage applied to the two heaters is controlled so that it isdifferent in each. The average is generated by pulsing a direct voltageapplied to each heater element or by controlling the level of thevoltage. In either case, as can be seen in this example, a user hasselected a configuration in which a higher “average” voltage is appliedto the first heater when compared to the second heater, enabling aroughly 60/40 portion of content from the two reservoirs to be used togenerate an aerosol for inhalation by a user.

FIG. 4b shows a second example in which a first heater is supplied withcurrent for a first period, and then switched off and the second heaterelement supplied. This enables the user to control the nature of theaerosol during an inhalation.

With all the examples of the present invention, switching of supply tothe battery may be provided by a user-activated switch or by aninhalation-activated switch, dependent upon consumer need.

FIG. 5 shows a further example of an aerosol generating device accordingto the present invention in the form of a non-heated aerosol generatingdevice. In this example the device of the invention again enables a userto control more readily the aerosol that they inhale and also enablingthe fresher mixing of components at the time of inhalation.

As can be seen from FIGS. 5A, 5B and 5C, a container is subdivided intotwo sections 40, 41, each of which contains a different fluid underpressure. Furthermore, a first and a second valves 42, 43 are alsoprovided and are respectively in fluid engagement with sections 41, 42through openings 44, 45. First and second valves 42, 43 have respectivechambers 46, 47 which receive fluid from sections 40, 41 for subsequentdispensing to a user when the device is operated via an aperture 48, 49(see FIG. 5C). The valves 42, 43 are configured such that they areselectively operable by a user through a mechanism (not shown) tooperate either the first valve 42 on its own, the second valve 43 on itsown, the first and second valves 42, 43, together, or one of the twovalves followed by the other in sequence. This enables a user tocollectively dispense the contents of the chambers 46, 47 individually,together or in sequence to control the flavour of the aerosol that theyinhale.

FIG. 6 shows an adaptation of the configuration of FIG. 5, in which twovalves 60, 61 are provided for a user to selectively control the releaseof fluid from two reservoirs 62 and 63. Each valve 60, 61 has aninternal metering chamber 65, 66 in fluid communication with thereservoirs 62, 63 through apertures 67, 68. In addition, each valve 60,61 further has a discharge opening 69, 70 to release a dose of fluidfrom each reservoirs 62, 63 to form an aerosol. In this example anadjustment mechanism 64 is provided which engages with either one orboth of the valve mechanisms 60, 61 of one or more of their respectivechambers 62, 63. Actuation of component 64 by a user and thereforeadjustment of the relative sizes of the chambers 65 and 66 is possiblefor a user to select the proportions of the doses of fluid provided fromthe reservoirs 62, 63 when the user operates the device to receive theaerosol.

FIG. 7 shows a schematic diagram showing a further example of an aerosolgenerating device according to the present invention in the form of anebuliser. In this example two liquids are provided 80, 81 in separatecompartments and pass through respective conduits 82, 83. A gas inlet 84is provided, but this time the flow of the liquids 80, 81 and gaspassing through the gas inlet 84 is controlled by a valve 85 to enablecontrol of the relative proportions of the liquids 80, 81 which aremixed with the gas to form the aerosol. Again, a user controls the flowof aerosol by controlling the supply of gas to the valve 85, but in thisexample of the present invention, as with others, the user is able tocontrol the relative mixing of the liquids 80 and 81 to control thenature of the aerosol that is inhaled in accordance with their wishes.

As mentioned above, all of the examples of the present invention enablethe provision of an aerosol-generating device with improved consumerexperience through the ability of the consumer to control more readilythe aerosol that they inhale, as well as also enabling the provision of“fresher” mixing of the components of the aerosol generating liquid.

1. (canceled)
 2. An electronic cigarette comprising: a mouthpieceportion including at least two reservoirs, each arranged to contain aseparate aerosol producing composition, and a bridge for drawing thecompositions from the reservoirs to generate an aerosol for inhalationfor a user; and a mixing valve for selectively mixing the compositionsafter they have been drawn from the reservoirs, the mixing valvearranged to allow a user to select the relative proportions of the twocompounds in the aerosol.
 3. The electronic cigarette according to claim2, wherein at least one of the reservoirs comprises a flavorant.
 4. Theelectronic cigarette according to claim 2, further comprising: a powersource; at least one heater assembly; a switch for selectively supplyingpower from the power source to the heater assembly; and a control switchor valve for selectively controlling the heating of liquid from one ormore of the reservoirs by the heater assembly, such that, when power issupplied to the heater assembly together with the selected liquid, anaerosol is generated for inhalation by a user.
 5. An electroniccigarette according to claim 4, wherein the switch is activated by auser drawing air through the electronic cigarette.
 6. The electroniccigarette according to claim 5, wherein the control valve can beoperated to selectively connect one or another of the liquid reservoirs,or every liquid reservoir at the same time to a transfer element formingpart of the at least one heater assembly.
 7. The electronic cigaretteaccording to claim 6, wherein the at least one heater assembly comprisesa heating element associated with each liquid reservoir, and the controlvalve is arranged such that a user can select the amount of power to beapplied to each heating element to thereby control the amount of liquidfrom each reservoir that is used to generate the aerosol.
 8. Theelectronic cigarette according to claim 7, wherein the control valve isarranged to allow alternate pulsed power supply to each heating elementof the heater assembly.
 9. The electronic cigarette according to claim8, wherein the at least one heater assembly has a heating elementassociated with each liquid reservoir and the control valve controls theflow of air over each heating element, thereby controlling the amount ofliquid that is used from each reservoir to generate the aerosol.
 10. Theelectronic cigarette according to claim 3, further comprising anelongated body into which said control switch or valve is embedded, saidmouthpiece portion further comprising at least one air intake for a userto draw air inside the elongated body to mix with said aerosol and toinhale the mixed aerosol composition through the mouthpiece portion. 11.The electronic cigarette according to claim 2, wherein the at least tworeservoirs are refillable.
 12. The electronic cigarette according toclaim 2, wherein the mouthpiece portion is disposable.
 13. An electroniccigarette comprising: a mouthpiece portion including at least tworeservoirs, each arranged to contain a separate aerosol producingcomposition and each reservoir being connected to a separate heaterassembly and a bridge for drawing the compositions from the reservoirsto generate an aerosol for inhalation for a user, and a control switchfor selectively controlling the heating of liquid from one or more ofthe reservoirs by the heater assembly, such that, when power is suppliedto the heater assembly together with the selected liquid, an aerosol isgenerated for inhalation by a user.
 14. The electronic cigaretteaccording to claim 13, wherein at least one of the reservoirs comprisesa flavorant.
 15. The electronic cigarette according to claim 13, furthercomprising an elongated body into which said control switch or valve isembedded, said mouthpiece portion further comprising at least one airintake for a user to draw air inside the elongated body to mix with saidaerosol and to inhale the mixed aerosol composition through themouthpiece portion.
 16. An electronic cigarette comprising: a mouthpieceportion including at least two reservoirs, each arranged to contain aseparate aerosol producing composition, and a pair of drawing valves fordrawing the compositions from the reservoirs to generate an aerosol forinhalation for a user; and a mixing valve for selectively mixing thecompositions after they have been drawn from the reservoirs, the mixingvalve arranged to allow a user to select the relative proportions of thetwo compounds in the aerosol.
 17. The electronic cigarette according toclaim 16, wherein at least one of the reservoirs comprises a flavorant.18. The electronic cigarette according to claim 16, further comprising:a power source; at least one heater assembly; a switch for selectivelysupplying power from the power source to the heater assembly; and acontrol switch or valve for selectively controlling the heating ofliquid from one or more of the reservoirs by the heater assembly, suchthat, when power is supplied to the heater assembly together with theselected liquid, an aerosol is generated for inhalation by a user. 19.The electronic cigarette according to claim 16, further comprising anelongated body into which said control switch or valve is embedded, saidmouthpiece portion further comprising at least one air intake for a userto draw air inside the elongated body to mix with said aerosol and toinhale the mixed aerosol composition through the mouthpiece portion. 20.The electronic cigarette according to claim 16, wherein the reservoirsare arranged to hold the compounds under pressure; and the pair ofdrawing valves includes one for each reservoir.
 21. The electroniccigarette according to claim 16, wherein each of the drawing valves isarranged to provide a predetermined amount of its respective compound.22. The electronic cigarette according to claim 16, wherein the mixingvalve can vary the dose of compound provided by one or both of thevalves.
 23. The electronic cigarette according to claim 16, furthercomprising a source of high pressure gas to aid in drawing the compoundsfrom the reservoirs through the pair of drawing valves; and wherein themixing valve is a variable proportion valve.
 24. A mouthpiece sectionfor an electronic cigarette comprising: at least two reservoirs, eacharranged to contain a separate aerosol producing composition; wherein atleast one of the reservoirs comprises a flavorant; a bridge for drawingthe compositions from the reservoirs to generate an aerosol forinhalation for a user, and a mixing valve for selectively mixing thecompositions after they have been drawn from the reservoirs, the mixingvalve being arranged to allow a user to select the relative proportionsof the two compounds in the aerosol.
 25. A mouthpiece section for anelectronic cigarette comprising: at least two reservoirs, each arrangedto contain a separate aerosol producing composition; wherein at leastone of the reservoirs comprises a flavorant; a pair of drawing valvesfor drawing the compositions from the reservoirs to generate an aerosolfor inhalation for a user, and a mixing valve for selectively mixing thecompositions after they have been drawn from the reservoirs, the mixingvalve being arranged to allow a user to select the relative proportionsof the two compounds in the aerosol.